Quantum dots with mixed amine and thiol ligands

Abstract

The present disclosure provides a liquid quantum dots composite that includes: a fluorescent semiconductor core/shell nanoparticle (preferably, nanocrystal or quantum dots); a first polyamine ligand and a second polythiol ligand attached to the core/shell nanoparticle outer surface. At least one of the polythiol and polyamine ligands are silicone ligands.

What is claimed is: 
     
       1. A liquid composite comprising a fluorescent core/shell semiconductor nanoparticle, a first polyamine ligand, and second polythiol ligand, wherein at least one of said first and second ligand is a silicone ligand. 
     
     
       2. The liquid composite of  claim 1  wherein the first ligand and the second ligand is at least 50% by weight of the liquid composite. 
     
     
       3. The liquid composite of  claim 1  wherein the fluorescent core/shell semiconductor nanoparticle is a CdS or CdSe core nanoparticle. 
     
     
       4. The liquid composite of  claim 1  comprising an aminosilicone and a mercaptosilicone. 
     
     
       5. The liquid composite of  claim 1  wherein the shell comprises a magnesium or zinc-containing compound. 
     
     
       6. The liquid composite of  claim 1  wherein the shell is a multilayered shell. 
     
     
       7. The liquid composite of  claim 6  wherein the multilayered shell comprises an inner shell overcoating the core, wherein the inner shell comprises zinc selenide and zinc sulfide. 
     
     
       8. The liquid composite of  claim 7  wherein the multilayered shell comprises an outer shell overcoating the inner shell, wherein the outer shell comprises zinc sulfide or MgS. 
     
     
       9. The liquid composite of  claim 1  wherein the polythiol is of the formula:
   R 2 (SH) y   I
 
 where R 2  is silicone or a (hetero)hydrocarbyl group having a valence of y, and y is ≥2, preferably >2. 
 
     
     
       10. The liquid composite of  claim 1  wherein the polythiols are obtained by esterification of a polyol with a terminally thiol-substituted carboxylic acid or derivative thereof. 
     
     
       11. The liquid composite of  claim 1  wherein the polyamine is an aminosilicone is of the formula: 
       
         
           
           
               
               
           
         
         wherein 
         each of R 1  and R 6  is independently an alkyl or aryl; 
         R 2  is a n amine-substituted (hetero)hydrocarbyl group; 
         x is 1 to 2000; preferably 3 to 100; 
         y may be zero; 
         x+y is at least one; 
         R 7  is alkyl, aryl or R NH2    
         wherein amine-functional silicone has at least two R NH2  groups. 
       
     
     
       12. The liquid composite of  claim 1  further comprising one or more auxiliary ligands of the formula:
   R 15 —R 12 (Z) z   VIII
 
 wherein 
 R 15  is (hetero)hydrocarbyl group having C 2  to C 30  carbon atoms; 
 R 12  is a hydrocarbyl group including alkylene, arylene, alkarylene and aralkylene; 
 subscript z is at least one; and 
 Z is a ligand group, including —CO 2 H, —SO 3 H, —P(O)(OH) 2 , —OP(O)(OH), —OH and —NH 2 . 
 
     
     
       13. A composition comprising the liquid composite of  claim 1  further comprising a curable liquid binder composition. 
     
     
       14. The composition of  claim 13  comprising red and green fluorescent core/shell semiconductor nanoparticles. 
     
     
       15. The composition of  claim 13  wherein the curable liquid binder composition comprises a polythiol and a polyene, and optionally a thiol-ene curing initiator. 
     
     
       16. The composition of  claim 13  wherein the cured polymeric binder comprises polysiloxanes, fluoroelastomers, fluoroplastics, polyamides, polyimides, polycaprolactones, polycaprolactams, polyurethanes, polyvinyl alcohols, polyvinyl chlorides, polyvinyl acetates, polyesters, polycarbonates, polyacrylates, polymethacrylates, polythioethers, polyacrylamides, polyethers, polyurethanes, polythiourethanes, polyurea, polymethacrylamides and the combinations thereof. 
     
     
       17. An article comprising the liquid composite of  claim 1  dispersed in a cured polymeric binder. 
     
     
       18. The article of  claim 17  wherein the cured polymeric binder comprises polysiloxanes, fluoroelastomers, fluoroplastics, polyamides, polyimides, polycaprolactones, polycaprolactams, polyurethanes, poly(vinyl alcohols), poly(vinyl chlorides), poly(vinyl acetates), polyesters, polycarbonates, polyacrylates, polymethacrylates, polythioethers, polyacrylamides, polyethers, polyurethanes, polythiourethanes, polyurea, polymethacrylamides and the combinations thereof. 
     
     
       19. A quantum dot film article comprising:
 a first barrier layer; 
 a second barrier layer; and 
 a quantum dot layer between the first barrier layer and the second barrier layer, the quantum dot layer comprising the liquid composite of  claim 1 , the composite particles dispersed in a cured polymeric binder.